Hitting play more than once, causes an echo and I can't stop my mp3 player. What's the best practice for mp3 playback?

            var mySound:Sound = new Sound();
    playButton.addEventListener (MouseEvent.CLICK, myPlayButtonHandler);
            var myChannel:SoundChannel = new SoundChannel();

            function myPlayButtonHandler (e:MouseEvent):void {
                    myChannel = mySound.play();
                            }
    stopButton.addEventListener(MouseEvent.CLICK, onClickStop);
            function onClickStop(e:MouseEvent):void{
                            myChannel.stop();
                            }